Automatic motor control and oil-pressure gauge



June 22 1926.

P. B. NEWKIRK AUTOMATIC MOTOR CONTROL AND OIL PRESSURE GAUGE Filed July6, 1922 4 Sheets-Sheet 1 kirk,

PerrzyBul ew 6H0 nu,

June 22 1926. 1,589,545

' P. B. NEWKIRK AUTOMATIC MOTOR CONTROL AND OIL PRESSURE GAUGE FiledJuly 6, 1922 4 Sheets-Sheet 2 liQ'g. AZ.

June 22 ,1926. 1,589,545

P. B. NEWKIRK AUTOMATIC MOTOR CONTROL AND OIL PRESSURE GAUGE Filed July6, 1922 4 Sheets-Sheet 5 PerryBQAZ wliiirfi' Jim 22 1926.

P. B. NEWKIRK AUTOMATIC MOTOR CONTROL @ND OIL PRESSURE GAUGE Filed July6, 1922 4 Sheets-Sheet 4 Patented June 22, 19 26 UNITED STATES PATENTOFFICE.

PERRY B. nnwxmx, or SEATTLE, wasnmeron, ASSIGNOB or ONE-HALF TO JOHN E.

. sense, or romrmc, mronmum.

AUTOMATIC MOTOR CONTROL AND OIL-PRESSURE GAUGE.

Application filed July 6, 1922. Serial No. 573,075.

This invention relates to a pressure controlled electric switch which isadapted to short circuit the ignition circuit of a motor vehicle in casethe oil pressure fails and thereby stop the engine.

The object of my invention is to provide a switch mechanism which may beincorporated in the oil pressure gauges now in common use and may beeither attached to existing pressure gauges or when embodied in themanufacture of new gauges, the latter may readily be inserted in theplace of the old gauges without any other charge.

In the following description I shall refer to the accompanying drawings,in which- Figure 1 is a front elevation of the usual oil pressure gauge;Fig. 2 is a diagram of an engine ignition circuit with my automaticshort circuiting switch installed in the pressure gauge; Figs. 3 and 6are front elevations of a pressure gau e having my switch mechanismincorporate the cover plate being removed; Fig. 4 is a transversesectional view on the line 4-4 of Figs. 3 and 5; Fig. 5 is a rearelevation; Figs. 7 and 8 are enlarged detail views showing the switch.elements in diiferent positions; Figs. 9, 10 and 11 are respectivelyrear side and front elevations of a modified form of my invent1on.

In Fig. 2 I have shown a conventional dia- 'ram of an ignition circuitfrom the battery 8r source of current 12, through the main switch 14 tothe spark plugs of the engine cylinders 15, the timer or distributerbeing omitted from the diagram. My short-circuiting member is indicatedat 16 in the form of a pawl mounted on the indicator stem within thecasing 18 of the pressure gauge.

The parts of the presure gauge have been shown in the usual manner andwill be recognized by engineers. The Bourdon tubular spring 20 ismounted at its lower end, its bore being connected to the 011 pressuresystem by means of a union secured to the threaded nipple 21 (see Fig.4). The free end of the spring is connected by llnk 23 to the pivot endof a sector lever 24 having a segmental rack operating upon the pinion25 on the indicator shaft 26 which moves the pointer needle 27 over thedial scale 28. The glass cover plate 30 is held in the cover frame 31 bya spring ring 32 All of these parts are of the usual construction.

My combined main switch and automatic pressure controlledshort-circuiting device are incorporated in the oil pressure gauge asfollows: The conductor leads 34 and 35 of the ignition circuitareconnected to switch plates 36 and 37 secured to the back of thecasing but insulated therefrom. The switch blade 14 of the 'manuallyoperated main switch is secured to the rear end of the stem 38, havingon its front end the turning knob or switch button 40. In Fig. 5 theswitch blade 14 is shown in full lines in the running position and indotted lines in the off posi- I attach the short circuiting switch memher or pawl 16 to the indicator shaft 26 so that it is actuated inunison with the pointer needle by the sector lever in accordance withthe pressure changes in the Bourdon tube 20. lVhen full pressure is on,the pawl. 16 will be in the osition indicated in full lines in Fig. 3,an when the pressure falls it will swing over to the position indicatedin Fig. 6

In the path of the pawl is a stop contact 42, which may constitute theouter end of a wire or rod 42, secured to the switch plate 37. A springarm 43 fastened at its lower end, is positioned so that its free end isnormally out of the path of the pawl, as indicated in Figs. 3 and 6, themain circuit closing or main switch being then in running position.WVhen the switch is turned to off position, a cam lug 45 on the stem 38engages the spring arm and forces it over into the position indicated inFig. 8, so that the end of the arm will pass under the catch on the pawl16 when the latter is moved over into no pressure position.

In operation, when the oil pressure is operating under normal pressure,thepawl is maintained in the position shown in Fig. 3, the main switchbeing shown in the running position in this figure. If the oil pressureshould fail for any reason, such as low oil supply, broken pump or abroken or plugged oil line, the Bourdon tube will cause the pawl 16 toswing over into the position indicated in Fig. 6, thereby bringing thepawl into engagement with the contact 42. In the arrangement shown inFigs. 2 and 6 the pawl is grounded and the battery will nowbeshort-circuited or grounded through conductor lead 35, red 42*, and theauxiliary short-circuiting switch comprising the stop contact42 and pawl16, thus cutting cit the current from the spark plugs and stopping theengine. The ground connection can be made of such low resistance thatthe current will be practically shunted and yetnot absolutelyshort-circuit the battery. By turning the button 4.0 to rotate theswitch blade 14: into the off position the cam lug l5 forces the outerend of the spring arm i3 against the bevelled outer end of the pawl 16in the manner indicated in Fig. 7.. lhe inclined bent end of the springexerts a pressure upon the bevelled end of the pawl which causes it tomove from under the spring and then fall back with the spring under thecatch as indicated in Fig. 8. The pawl is thus separated from thecontact 42 and prevented by the spring arm from again engaging it, sothat the short circuit-ing path is broken. Therefore, when the troublehas been eliminated, the button 40 may be turned to close the mainswitch to again start the engine. Likewise if the trouble was causedmerely on account of low oil supply, the engine may be started after theparts have been first moved into the position shown in Fig. 8 to breakthe short-circuit, by then turning the main switch back into startingposition, so that the operator may drive his car cautiously for adistance sufiioient to reach an oil supply store or station.

It is evident that the spring arm 43 will always be moved over into thepath of the pawl when the switch is in the foff position. Hence, whenthe motor is stopped,'and the oil pressure falls, the pawl will bearrested in the position shown in Fig. 8 without coming into engagementwith the contact 42 and consequently" the battery will not beshortcircuit/ed, so that there will be no danger of discharging it whilethe car is not in use.

I have shown in Figs. 3, 9, 10, and 11, means for automatically openingthe main switch immediately after the pawl 16 has short-circuited theignition system and stopped the engine. In this case the shortcircuiting pawl 16 is insulated as by sleeve 26 from the shaft 26. Anauxiliary contact 50 carried by a terminal post 51 is located in thepath of the pawl 16. The post is connected by wire 52 to one terminal ofa s0lenoid 53, the other terminal 54 being grounded. A pin 56 projectingfrom the stem 38 of the main switch is operatively connected to theplunger or core 57 of the solenoid.

'When, therefore, the pawl 16 swings to the .left upon failure of theoil pressure, it engages simultaneously with contacts 42 and 50, therebyforming a shunt circuit from the battery through conductor 35, mainswitch plate 37 contact 42, pawl 16, contact 50, port 51, and solenoid53 to ground, thereby shunting the ignition. system. The solenoidimmediately draws in its plunger, rotating the shaft 38 and shiftin theswitch bladeu i from dotted line position to full line position in Fig.11, therebyopening the main circuit betweenuthe switch plates 36 and 37and stopping the engine. This automatic opening of the main circuiteliminates all danger of discharging the battery. The stem 38 may beprovided with a cam lug 45, as shown in Figs. 3 to 8, to cause the pawl16'to back off and permit the spring arm 43 to pass under the notch ofthe pawl in the manner indicated in Figs. 7 and 8 to thereby separate-from the contacts 42 and 50, so that the ignition circuit may be closedupon again turning the main switch into starting position.

I claim lid 2. An automatic short circuiting device,

nected to the main circuit and positioned in' the path of said member, aresilient arm normally out of the path of said member, and a main switchhaving means for moving said arm into the path of said member when saidswitch is moved to its ofi position.

2. An automatic short circuiting device, comprising a pivotally mountedfluid pressure controlled member, a stop contact connected to the maincircuit and positioned in the path of said member, a resilient armnormally out of the path of said member and a main switch having meansfor moving said arm against said member when the latter is in contactwith said stop contact to cause said resilient arm to move said memberaway from said stop contact and maintain it separated therefrom.

3. An automatic short circuiting device, in combination with an oilpressure gauge having an indicator shaft, comprising a short circuitingmember mounted upon the indicator shaft of the gauge, a stop contactconnected to the main circuit and positionedin the path of said member,a resilient arm normally out of the path of said member, and means'formoving said arm into said path to prevent the engagement of said memberwith said stop contact.

4. An automatic short circuiting device, in combination with an oilpressure gauge having an indicator shaft, comprising a short circuitingmember mounted upon the indicator shaft of the gauge, a stop contactconnected to the main circuit and positioned in the path of said member,a resilient arm normally out of the path of said member and means formoving said arm against said member when the latter is in engagementwith said'stop contact, thereby causing the yielding pressure of saidarm to separate said member from said stop contact and maintain itseparated therefrom.

in combination with an oil having an indicator shaft, short circuitingmembe indicator shaft of the connected to the main in the path of saidpressure gauge comprising a r mounted upon the gauge, a stop contactcircuit and ositioned member, sai member Serving to ground the maincircuit upon engaging said stop contact, and an electro magneticallyactuated switch operating to open the In test ture.

main circuit when thusgrounded.

imony whereof I aifix my signa- PERRY B. N EWKIRK.

